Voltage Regulator

[cudabob496]

I've always used the other blue MP regulator.
Is the below VR something new that I should use?

http://www.summitracing.com/parts/dcc-3690732/overview/

below is one I have been using

http://www.summitracing.com/parts/dcc-3690731/overview/

[734406pk]

The blue regulator is a Prestolite type used in industrial/marine applications. It's function is basically the same except it is a "B" type (regulates on the field positive side). The Mopar automotive regulator is an "A" type, regulating on the field negative side. You could re-wire your alternator to use the "B" type but I don't see an advantage. They are both "transistorized" regulators vs the mechanical type used back in the day. PNP transistor for one and NPN for the other. 

[dougs bs23]

so how do these blue units differ from the black one?
http://www.summitracing.com/parts/dcc-4529794/overview/

reason i ask is I notice my voltage meter fluctuate a little and at startup idle I notice the dome light flicker,  then poof the voltage dropped to 12 as if no charge at all.  Was an aftermarket unit,  change it out to a unit from my local napa which lasted 5 minutes then same thing happened,/
only have elec fuel pump on relays, the relay light system from crackedback and did install a bypass from alt to starter relay battery side terminal and a pioneer stereo wired through the fuse box so I don't really see a large load on the total system

[cudabob496]

The blue regulator is a Prestolite type used in industrial/marine applications. It's function is basically the same except it is a "B" type (regulates on the field positive side). The Mopar automotive regulator is an "A" type, regulating on the field negative side. You could re-wire your alternator to use the "B" type but I don't see an advantage. They are both "transistorized" regulators vs the mechanical type used back in the day. PNP transistor for one and NPN for the other. 

so the blue one with the dangling wire is the B type?

[734406pk]

so the blue one with the dangling wire is the B type?

Yes, that's right! The blue one is a "B" type regulator.

[734406pk]

so how do these blue units differ from the black one?
http://www.summitracing.com/parts/dcc-4529794/overview/

reason i ask is I notice my voltage meter fluctuate a little and at startup idle I notice the dome light flicker,  then poof the voltage dropped to 12 as if no charge at all.  Was an aftermarket unit,  change it out to a unit from my local napa which lasted 5 minutes then same thing happened,/
only have elec fuel pump on relays, the relay light system from crackedback and did install a bypass from alt to starter relay battery side terminal and a pioneer stereo wired through the fuse box so I don't really see a large load on the total system

This is a very common issue. The ignition circuit that supplies the ignition coil, alternator etc also powers up the regulator, electric choke element etc. 45+ year old wiring can become a resistance and cause a voltage drop to the regulator. The regulator senses low voltage and will increase the alternator field to compensate. Then voltage goes too high and the reg pulls back. This cycle can happen rapidly. Change the reg... same thing happens. The voltage drop from the positive battery terminal to the ignition power should be checked. Sounds like there is an issue there. Post back if you need help with this. You will need an accurate volt meter, preferably a digital.

[cudabob496]

the "A" type I've been using seem to fail about every 3 or 4 years.  Volts and amps start
going all over the place.  Now I'm going to carry a spare in the car.

[734406pk]

the "A" type I've been using seem to fail about every 3 or 4 years.  Volts and amps start
going all over the place.  Now I'm going to carry a spare in the car.

  Carry a spare!  My VR is starting to act up as well....With 3-4 years of use.

[734406pk]

A "single wire" alternator makes a lot of sense... No external regulator at all!

[Chryco Psycho]

The first one was used until 69 switching the + side , the second type which you are using switches the - side / less current & a better way to do it .
 Single wire alts makes sense until you have to replace a complete alternator for a $15 regulator which is built in , I like having the reg separate

[734406pk]

I found this regulator conversion kit to make your own single wire alternator. Here is the link:::
http://store.alternatorparts.com/partnod7018.aspx

[msbaugh]

I found this regulator conversion kit to make your own single wire alternator. Here is the link:::
http://store.alternatorparts.com/partnod7018.aspx

I have one of these on my alternator.  It's a tough stuff alternator... I think they just add these to the 3 fields to make them one wires?  What I need to figure out on this car though is why it still has a traditional VR on the firewall and how does the one wire split up to feed the resistor in the stock wiring harness.   

[734406pk]

I have one of these on my alternator.  It's a tough stuff alternator... I think they just add these to the 3 fields to make them one wires?  What I need to figure out on this car though is why it still has a traditional VR on the firewall and how does the one wire split up to feed the resistor in the stock wiring harness.   

That's the one! Transpo P/N 7018 regulator. The traditional firewall mounted reg would be disconnected from the alternator if you are using the one wire type. There is a splice in the engine harness for ignition hot to power the old regulator, ignition control etc... It's a Dark Blue wire with a tracer (from the bulkhead connector pin #23) for a '73 model year.

[msbaugh]

That's the one! Transpo P/N 7018 regulator. The traditional firewall mounted reg would be disconnected from the alternator if you are using the one wire type. There is a splice in the engine harness for ignition hot to power the old regulator, ignition control etc... It's a Dark Blue wire with a tracer (from the bulkhead connector pin #23) for a '73 model year.

734406pk,  thank you for the explanation!  Sorry to did up a somewhat old thread but I've mapped this whole thing out and have a question.... with the 1 wire alternator, why can't I just take the old VR off completely? Disconnect the dark blue wire that comes from terminal 23 like you said, and just remove it.  Since the alternator field wire isn't going to the other side of the old VR it actually isn't doing anything anyways, right?

[734406pk]

734406pk,  thank you for the explanation!  Sorry to did up a somewhat old thread but I've mapped this whole thing out and have a question.... with the 1 wire alternator, why can't I just take the old VR off completely? Disconnect the dark blue wire that comes from terminal 23 like you said, and just remove it.  Since the alternator field wire isn't going to the other side of the old VR it actually isn't doing anything anyways, right?

Yes you can remove the OEM regulator. There is a splice in the engine wiring harness forward of pin 23. The dark blue wire which feeds the reg and field positive is connected there. Do you have a wiring diagram? If not i can forward a PDF to you.